package com.cwz.gateway.config;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.gateway.config.GatewayProperties;
import org.springframework.cloud.gateway.route.RouteLocator;
import org.springframework.cloud.gateway.support.NameUtils;
import org.springframework.context.annotation.Lazy;
import org.springframework.stereotype.Component;
import org.springframework.web.reactive.config.ResourceHandlerRegistry;
import org.springframework.web.reactive.config.WebFluxConfigurer;
import springfox.documentation.swagger.web.SwaggerResource;
import springfox.documentation.swagger.web.SwaggerResourcesProvider;

import java.util.ArrayList;
import java.util.List;

/**
 * @program: w-demo
 * @description: 聚合系统 Swagger 接口
 * 因为每个微服务都会有一个 Swagger，这样查看起来就很麻烦，所以这里我就把所有微服务的 Swagger
 * 聚合到网关，网关打开总 Swagger 选择对应的微服务查看对应的 Swagger 接口
 * @author: Wen
 **/
@Component
public class SwaggerProvider implements SwaggerResourcesProvider, WebFluxConfigurer {
	// Swagger 地址：http://localhost:6800/swagger-ui/index.html
	/**
	 * Swagger2默认的url后缀
	 */
	public static final String SWAGGER2URL = "/v2/api-docs";

	/**
	 * 网关路由
	 */
	@Lazy
	@Autowired
	private RouteLocator routeLocator;

	@Autowired
	private GatewayProperties gatewayProperties;

	/**
	 * 聚合其他服务接口
	 *
	 * @return
	 */
	@Override
	public List<SwaggerResource> get() {
		List<SwaggerResource> resourceList = new ArrayList<>();
		List<String> routes = new ArrayList<>();
		// 获取网关中配置的route
		routeLocator.getRoutes().subscribe(route -> routes.add(route.getId()));
		gatewayProperties.getRoutes().stream()
			// 过滤掉网关配置文件中没有配置的 route
			.filter(routeDefinition -> routes.contains(routeDefinition.getId()))
			.forEach(routeDefinition -> routeDefinition.getPredicates().stream()
				// 找出 predicates 包含 Path 的路由
				.filter(predicateDefinition -> "Path".equalsIgnoreCase(predicateDefinition.getName()))
				// cwz-auth 的路由不加上 swagger
				//.filter(predicateDefinition -> !"cwz-auth".equalsIgnoreCase(routeDefinition.getId()))
				.forEach(predicateDefinition -> resourceList
					.add(swaggerResource(routeDefinition.getId(), predicateDefinition.getArgs()
						.get(NameUtils.GENERATED_NAME_PREFIX + "0").replace("/**", SWAGGER2URL)))));
		return resourceList;
	}

	private SwaggerResource swaggerResource(String name, String location) {
		SwaggerResource swaggerResource = new SwaggerResource();
		swaggerResource.setName(name);
		swaggerResource.setLocation(location);
		swaggerResource.setSwaggerVersion("2.0");
		return swaggerResource;
	}

	@Override
	public void addResourceHandlers(ResourceHandlerRegistry registry) {
		/** swagger-ui 地址 */
		registry.addResourceHandler("/swagger-ui/**")
			.addResourceLocations("classpath:/META-INF/resources/webjars/springfox-swagger-ui/");
	}
}
